This WordPress plugin can add a sidebar widget for subscribing to MailChimp-powered newsletter. It can simply collects user emails and stores them to a preset personal MailChimp account.

Features of MailChimp Widget:- Easy to use- AJAX-enabled, but degrades gracefully if Javascript isn't turned on- Encourages the collection of only information that you actually need (i.e., an email address) to send mails

Requirements:- WordPress 3.0.1 or Higher

Installation:- Unpack and upload it to the /wp-content/plugins/ directory. Activate the plugin through the 'Plugins' menu in WordPress.